Seat belt device

ABSTRACT

A seat belt device allows easy connection of a lap anchor fixed to one end of a seat belt relative to a vehicle body or the like even when a seat weight sensor is installed below a vehicle seat. The seat weight sensor and the vehicle seat are fixed to a vehicle body floor. A hitch member is attached to the seat weight sensor via a mounting bracket by a bolt. A lap anchor is locked to a hitch member by an engaging hook of the lap anchor. The hitch member is directly attached to a mounting bracket of the seat weight sensor. The mounting bracket is positioned between a seat rail and the seat weight sensor.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

This application is a Divisional Application of U.S. patent applicationSer. No. 10/718,543, filed Nov. 24, 2003, which is incorporated hereinby reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention pertains to a technical field of a seat beltdevice of which a seat belt for restraining and protecting an occupantsitting on a vehicle seat is connected to a vehicle body on a side ofthe vehicle seat and, particularly, to a technical field of a seat beltdevice for a vehicle seat which is provided at its lower portion with aseat weight sensor for measuring a seat load applied to the vehicleseat.

Conventionally, a seat belt device installed in a vehicle such as anautomobile prevents an occupant from jumping out of a vehicle seat byrestraining the occupant with a seat belt thereof, thereby protectingthe occupant in the event of emergency.

As such seat belt device, three-point-type seat belt devices which areconventionally well known are generally employed. In a three-point-typeseat belt device, one end of a seat belt is connected to a vehicle bodyor a vehicle seat fixed to the vehicle body on a side of the vehicleseat via a lap anchor fixed to the seat belt, while the other end of theseat belt is connected to a seat belt retractor. In this case, a middleportion of the seat belt is guided by a deflective fitting attached toan upper portion of a side of the vehicle body.

When the seat belt is not worn, the seat belt is wound by the seat beltretractor and is positioned to extend along the side of the vehiclebody. By latching a tongue slidably supported by the seat belt with abuckle fixed to the vehicle body on the opposite side of the lap anchorside about the vehicle seat, an occupant sitting in the vehicle seatputs on the seat belt. In this state, a portion of the seat belt betweenthe tongue and the deflective fitting (seat belt retractor side)functions as a shoulder belt for restraining and protecting an upperbody of the occupant from his or her shoulder to his or her chest, whilea portion of the seat belt between the tongue and the lap anchorfunctions as a lap belt for restraining and protecting a lower body ofthe occupant such as his or her abdomen.

On the other hand, in recent years, it has been developed to control theaction of the seat belt device depending on the weight (body weight) ofthe occupant. In such seat belt device, a seat weight sensor formeasuring the seat load, applied to the vehicle seat by the weight ofthe occupant and the like, is installed below the vehicle seat andbetween the vehicle seat and a vehicle body floor. By controlling theaction of the seat belt device depending on the weight of the occupantbased on the seat load measured by the seat weight sensor, the occupantcan be effectively restrained by the seat belt, as described in JapanesePatent Unexamined Publication No. H11-304579, and Japanese PatentUnexamined Publication No. H11-351952 (both incorporated by reference).

In the seat belt device for the vehicle seat which is provided at itslower portion with the seat weight sensor, the lap anchor for connectingone end of the seat belt to a vehicle body is positioned on a side ofthe seat weight sensor. However, since convex structural components ofthe vehicle body such as a pillar and a side sill depending on thevehicle structure exist on the side of the seat weight sensor, the spaceon the side of the seat weight sensor must be significantly narrow.Therefore, it is a bother and thus difficult to connect the lap anchorfixed to the end of the seat belt to the vehicle body floor or thevehicle seat or the seat weight sensor fixed to the vehicle body so thatthe work for this must require a lot of labor and time.

SUMMARY OF THE INVENTION

The present invention was made under the aforementioned circumstancesand the object of the present invention is to provide a seat belt devicewhich allows easy connection of a lap anchor fixed to one end of a seatbelt relative to a vehicle body or the like even when a seat weightsensor is installed below a vehicle seat.

To solve the aforementioned problems, the present invention is a seatbelt device comprising a seat belt for restraining and protecting anoccupant sitting on a vehicle seat, and a lap anchor fixed to an end ofthe seat belt, wherein the seat belt is connected to a vehicle body on aside of the vehicle seat via the lap anchor, a seat weight sensorinstalled below the vehicle seat measures a seat load applied to saidvehicle seat, and the action of the seat belt device is controlled onthe basis of the measured value of the seat load, and a hitch member isattached to either one of said vehicle body, said vehicle seat fixed tothe vehicle body, or said seat weight sensor fixed to the vehicle body;and that said lap anchor is locked to the hitch member.

The present invention further comprises a locking member for preventingthe release of the locking between said lap anchor and said hitchmember.

The hitch member of an embodiment of the present invention comprises aslide bar of which one end is attached to said seat weight sensor, whichextends from said one end toward the rear of the vehicle, and of whichthe other end is attached to the vehicle body and that said lap anchoris connected to said slide bar such that said lap anchor is movablealong said slide bar. According to embodiments of the present invention,an end of the seat belt can be easily connected to a vehicle body evenwhen a seat weight sensor is installed below a vehicle seat, just bylocking a lap anchor fixed to the end of the seat belt to a hitch memberattached to either one of the vehicle body, the vehicle seat fixed tothe vehicle body, or the seat weight sensor fixed to the vehicle body.Accordingly, the labor and time required for connecting the seat beltcan be significantly reduced, thus improving the workability and theproductivity.

Since the locking member is provided, the locking between the lap anchorand the hitch member is prevented from being easily released by thelocking member.

Further, according to another embodiment, in case that the seat beltdevice is installed to a vehicle such as a vehicle of two-door type,when a rear seat passenger is about to get on or off the vehicle, thelap anchor is moved along the slide bar so that the lap anchor is set atits standby position and then the rear seat passenger gets on or off thevehicle. Therefore, the lap belt does not disturb the action of thepassenger because the lap anchor is set at the standby position, therebyallowing the passenger to easily get in or out of the vehicle. After thepassenger gets in the vehicle, an occupant sitting on a front seat cannormally put on the seat belt by setting the lap anchor at its workingposition.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and exemplary only, andare not restrictive of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become apparent from the following description, appendedclaims, and the accompanying exemplary embodiments shown in thedrawings, which are briefly described below.

FIG. 1 is an illustration schematically showing an example of anembodiment of a seat belt device according to the present invention thatis adopted to a three-point seat belt device.

FIGS. 2( a), 2(b) specifically show portions of the seat belt device ofan embodiment wherein FIG. 2( a) is a rear view partially showing theseat belt device and FIG. 2( b) is a side view partially showing theseat belt device.

FIG. 3 is a perspective view schematically showing a lap anchor and ahitch member used in the embodiment shown in FIGS. 2( a), 2(b).

FIGS. 4( a), 4(b) are illustrations similar to FIGS. 2( a), 2(b), butshowing another embodiment of the present invention wherein FIG. 4( a)is a rear view partially showing the seat belt device and FIG. 4( b) isa side view partially showing the seat belt device.

FIGS. 5( a), 5(b) are illustrations similar to FIGS. 2( a), 2(b), butshowing still another embodiment of the present invention wherein FIG.5( a) is a rear view partially showing the seat belt device and FIG. 5(b) is a side view partially showing the seat belt device.

FIGS. 6( a), 6(b) schematically show a lap anchor and a hitch memberused in the embodiment shown in FIGS. 5( a), 5(b) wherein FIG. 6( a) isa perspective view thereof and FIG. 6( b) is an illustration showing thelocked state.

FIG. 7 is similar to FIGS. 6( a), 6(b) but schematically showing a lapanchor and a hitch member of further another embodiment of the presentinvention wherein FIG. 7 is a perspective view thereof.

FIGS. 8( a), 8(b) are illustrations similar to FIG. 1, but showingvariation examples of the present invention wherein FIG. 8( a) shows avariation example and FIG. 8( b) shows another variation example.

FIG. 9 is an illustration schematically and partially showing a lapanchor and a hitch member according to further another embodiment of thepresent invention.

FIGS. 10( a)-10(e) show a portion including the seat weight sensor and aslide bar shown in FIG. 9, wherein FIG. 10( a) is a plan view thereof,FIG. 10( b) is a side view thereof, FIG. 10( c) is a sectional viewtaken along a line XC-XC in FIG. 10( b), FIG. 10( d) is a partial viewof a side wall of a mounting bracket when seen in a direction of arrowXD in FIG. 10( a), and FIG. 10( e) is a partial view of the slide bar ata portion XE in FIG. 10( a).

FIGS. 11( a), 11(b) are illustrations for explaining the attachment ofthe slide bar to the weight sensor, wherein FIG. 11( a) is a partiallyexploded view of one end side of the slide bar and FIG. 11( b) is apartially exploded view of the other end side of the slide bar at aportion XIB in FIG. 10( b).

FIGS. 12( a), 12(b) show another example of the mounting portion betweenthe seat weight sensor and the slide bar, wherein FIGS. 12 (a) and 12(b)are sectional views similar to FIGS. 10( d) and 10(e).

FIG. 13 is a sectional view similar to FIG. 10( c) showing a variationof the mounting portion between the seat weight sensor and the slidebar.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present invention will be described withreference to the attached drawings.

FIG. 1 is an illustration schematically showing an example to which anembodiment of a seat belt device according to the present invention isadopted to a three-point seat belt device, and FIGS. 2( a), 2(b)specifically show portions of the seat belt device of this embodimentwherein FIG. 2( a) is a rear view partially showing the seat belt deviceand FIG. 2( b) is a side view partially showing the seat belt device.

As shown in FIG. 1, the seat belt device 1 of this embodiment is athree-point seat belt device which comprises a seat belt 2, a seat beltretractor 3 for winding up the seat belt 2, a deflective fitting 4attached to a vehicle body such as a center pillar, and a tongue 5slidably supported by the seat belt 2. The seat belt device 1 comprisesa buckle 6 to which the tongue 5 is detachably latched and a lap anchor7 fixed to an end opposite to the end of the seat belt 2 to which theretractor 3 is connected. However, there is a different point from theconventional seat belt device that the buckle 6 and the lap anchor 7 areattached to a vehicle seat 9 provided at its lower portion with a seatweight sensor (described later) or attached to the seat weight sensor(in the example shown in FIGS. 2( a), 2(b), the lap anchor 7 is attachedto the seat weight sensor). All the seat belt 2, the seat belt retractor3, the deflective fitting 4, the tongue 5 and the buckle 6 are the sameas used in the conventional typical three-point seat belt device, thatis, well known, so the detail description of these components will beomitted.

As shown in FIGS. 2( a) and 2(b), similarly to the seat belt devicesdisclosed in the aforementioned Japanese Patent Unexamined PublicationNo. H11-304579, and Japanese Patent Unexamined Publication No.H11-351952 (both incorporated by reference), a seat rail 10 is fixedbelow the vehicle seat 9 and a seat bracket 12 is fixed to a vehiclebody floor 11 such that the seat weight sensor 8 is disposed between theseat rail 10 and the seat bracket 12, i.e. below the vehicle seat 9.This seat weight sensor 8 is designed to measure the load applied to thevehicle seat 9. The seat weight sensor 8 is also the same as disclosedin the aforementioned Japanese Patent Unexamined Publication No.H11-304579 and Japanese Patent Unexamined Publication No. H11-351952(both incorporated by reference), so the detailed description of thiswill be omitted. It should be noted that the seat weight sensor 8 is notlimited to the seat weight sensor disclosed in Japanese PatentUnexamined Publication No. H11-304579 and Japanese Patent UnexaminedPublication No. H11-351952 (both incorporated by reference), and may beanother seat weight sensor which is conventionally known.

Between the seat rail 10 and the seat weight sensor 8, the seat weightsensor 8 is provided with a mounting bracket 13. A hitch member 14 isattached to the mounting bracket 13 by a bolt 15. As schematically shownin FIG. 3, the hitch member 14 has a casing 14 a, and a supportingmember 14 c to which the casing 14 a is supported by a mounting pin 14h. The supporting member 14 c is attached to a mounting bracket 13.

On the other hand, the lap anchor 7 is fixed to an end 2 a of the seatbelt 2 opposite to the retractor side by folding a portion of the seatbelt 2 after passed through a hole 7 a of the lap anchor 7 and thensewing together the folded portion. The lap anchor 7 comprises anengaging hook 7 b having an engaging concavity 7 b ₁. By inserting theengaging hook 7 b into the casing 14 a through an insertion opening 14 a₁ formed in the casing 14 a of the hitch member 14 and engaging theengaging hook 7 b with an engageable portion which is not shown, the lapanchor 7 is locked to the hitch member 14 [FIGS. 2( a) and 2(b) show astate where the lap anchor 7 is locked to the hitch member 14]. Thoughthe locking mechanism between the lap anchor 7 and the hitch member 14is not concretely shown in FIG. 3, the locking mechanism may be any ofconventionally known locking mechanisms, such as a conventionally knownlocking mechanism between a buckle and a tongue, which can lock the lapanchor 7 to the hitch member 14 when the lap anchor 7 is inserted intothe casing. Therefore, the concrete description of the locking mechanismwill be omitted. Moreover, the lap anchor 7 and the hitch member 14 maybe designed not to allow the release of the locking therebetween or maybe designed to allow the release of the locking therebetween by means ofa release operation member such as a release button. When the lap anchor7 and the hitch member 14 are designed to allow the release of thelocking therebetween, it is preferable that the release operation is adifficult task.

In the seat belt device 1 of this embodiment having the aforementionedstructure, the seat weight sensor 8 and the vehicle seat 9 are fixed tothe vehicle body floor 11 in a state that the hitch member 14 ispreviously mounted to the seat weight sensor 8 via the mounting bracket13 and the bolt 15 and, after that, the lap anchor 7 fixed to the end 2a of the seat belt 2 is locked to the hitch member 14 as mentionedabove, thereby connecting the end 2 a of the seat belt 2 to the hitchmember 14 (that is, the vehicle body).

Therefore, according to the seat belt device 1 of this embodiment, theend 2 a of the seat belt 2 can be easily connected to the hitch member14 just by locking the lap anchor 7 to the hitch member 14 even when theseat weight sensor 8 is installed under the vehicle seat 9. Accordingly,the labor and time required for connecting the seat belt 2 can besignificantly reduced, thus improving the workability and theproductivity.

Since the buckle 6 and the hitch member 14 are attached to the seatweight sensor 8, the seat weight sensor 8 is prevented from beinginfluenced by belt tension from the buckle 6 side or belt tension fromthe hitch member 14 side so that the seat weight sensor 8 can detect theactual seat load.

FIGS. 4( a), 4(b) are illustrations showing another embodiment of thepresent invention. In the following description of respectiveembodiments, the same components as those of the preceding embodiment(s)are marked with the same numerals, so detail description of thecomponents will be omitted.

Though the hitch member 14 is attached to the seat weight sensor 8 inthe aforementioned embodiment shown in FIGS. 2( a), 2(b), a hitch member14 is attached to a side 9 a of a vehicle seat 9 in a seat belt device 1of this embodiment as shown in FIGS. 4( a), 4(b)

The other structure of the seat belt device of this embodiment is thesame as that of the embodiment shown in FIG. 1 through FIG. 3. The worksand effects of the seat belt device 1 of this embodiment are also thesame as those of the embodiment shown in FIG. 1 through FIG. 3.

FIGS. 5( a), 5(b) are illustrations similar to FIGS. 2( a), 2(b), butshowing another embodiment of the present invention and FIGS. 6( a),6(b) schematically show a lap anchor and a hitch member used in thisembodiment wherein FIG. 6( a) is a rear view thereof and FIG. 6( b) is aside view thereof.

As shown in FIGS. 5( a) and 5(b), a hitch member 14 of a seat beltdevice 1 is attached to a seat weight sensor 8 similarly to theembodiment shown in FIGS. 2( a), 2(b). The hitch member 14 is attachedto the seat weight sensor 8 using a mounting bracket 13 and a bolt 15 inthe same manner as shown in FIGS. 2( a), 2(b).

In the aforementioned embodiment shown in FIGS. 2( a), 2(b), theengaging hook 7 b of the lap anchor 7 is inserted into the casing 14 aof the hitch member 14 and is engaged with the engageable portion insidethe casing. As shown in FIG. 6( a), however, the structures and thelocking method of the hitch member 14 and the lap anchor 7 of the seatbelt device 1 according to this embodiment are different from theembodiment shown in FIGS. 2( a), 2(b). That is, the hitch member 14 ofthis embodiment has a body 14 d composed of a rectangular flat plate, acylindrical engageable portion 14 b formed on a portion near one end ofthe body 14 d, and a circular mounting hole 14 e formed in a portionnear the other end of the body 14 d through which the mounting bolt 15is inserted. In this case, formed at the end of the engageable portion14 b is a circular falling preventive flange 14 f which has a diameterlarger than the diameter of the engageable portion 14 b.

On the other hand, the lap anchor 7 is composed of a rectangular flatplate similarly to the body 14 d of the hitch member 14 and has a hole 7a formed in a portion near an end, through which the end 2 a of the seatbelt 2 is passed. A portion of the lap anchor 7 extending from themiddle to the other end is an engaging portion 7 b. The engaging portion7 b is provided with an engaging hole 7 c which is formed in aguitar-shape comprising a large diameter hole 7 c ₁, a small diameterhole 7 c ₂, and a boundary portion 7 c ₃ at which the holes 7 c ₁ and 7c ₂ are partly superposed on each other. The diameter of the largediameter hole 7 c ₁ is set to be larger than the diameter of the fallingpreventive flange 14 f so that the flange 14 f can pass through thelarge diameter hole 7 c ₁. The diameter of the small diameter hole 7 c ₂is set to be larger than the diameter of the engageable portion 14 b andsmaller than the diameter of the flange 14 f so that the engageableportion 14 b can pass through the small diameter hole 7 c ₂, but thefalling preventive flange 14 f can not pass through the small diameterhole 7 c ₂. Further, the width of the boundary portion 7 c 3 between thelarge diameter hole 7 c ₁ and the small diameter hole 7 c ₂ is set toallow the engageable portion 14 b to pass through the boundary portion 7c ₃.

Further, a locking member 16 is provided. The locking member 16comprises a body 16 a having such a diameter that it can be fitted inthe large diameter hole 7 c ₁ and can not pass through the boundaryportion 7 c ₃, a circular flange 16 b which is formed on one end of thebody 16 a and has such a diameter that it can not be fitted in the largediameter hole 7 c ₁, and a retaining portion 16 c which is formed in theperipheries of the body 16 a and the circular flange 16 b and has an arcconcave shape of which diameter is the same as the diameter of theengageable portion 14 b.

As shown in FIGS. 5( a) and 5(b), the mounting bracket 13 is fixed tothe seat weight sensor 8. The lap anchor 7 fixed to the seat belt 2 isbrought to encircle the engageable portion 14 b and the fallingpreventive flange 14 of the hitch member 14, secured to the mountingbracket 13 by the bolt 15, such that the large diameter hole 7 c ₁ ofthe lap anchor 7 passes over the falling preventive flange 14 f and ispositioned around the engageable portion 14 b. After that, the lapanchor 7 is moved to pass the boundary portion 7 c ₃ such that theengageable portion 14 b is positioned in the small hole 7 c ₂. As shownin FIG. 6( b), in the state that the lap anchor 7 is in contact with thebody 14 d of the hitch member 14, the body 16 a of the locking member 16is fitted into the large-diameter hole 7 c ₁ such a manner that theretaining portion 16 c faces the outer surface of the engageable portion14 b.

At this point, the body 16 a of the locking member 16 is almostsandwiched between the falling preventive flange 14 f and the body 14 dso that the locking member 16 is prevented from falling off by thefalling preventive flange 14 f. In this state, the retaining portion 16c of the locking member 16 faces the outer surface of the engageableportion 14 b, thereby preventing the engageable portion 14 b fromshifting toward the large diameter hole 7 c ₁. Therefore, the lockingbetween the hitch member 14 and the lap anchor 7 is ensured, therebypreventing undesirable release between the hitch member 14 and the lapanchor 7. In this manner, the lap anchor 7 fixed to the end 2 a of theseat belt 2 is locked to the hitch member 14 so that the seat belt 2 isconnected to the hitch member 14, i.e. the vehicle body.

The other structure, works and effects of the seat belt device 1 of thisembodiment are the same as those of the embodiment shown in FIG. 1through FIG. 3. The hitch member 14 of this embodiment may be attachedto the vehicle seat 9 similarly to the embodiment shown in FIGS. 4( a),4(b).

FIG. 7 is an illustration similar to FIG. 6( a), but showing anotherembodiment of the present invention and schematically showing a lapanchor and a hitch member employed in this embodiment.

In the aforementioned embodiment shown in FIGS. 6( a), 6(b), the lapanchor 7 is locked to the hitch member 14 by inserting the engageableportion 14 b projecting from the body 14 a of the hitch member 14 intothe guitar-shaped engaging hole 7 c of the lap anchor 7, and the releasebetween the lap anchor 7 and the hitch member 14 is prevented by meansof the locking member 16. In a seat belt device 1 of this embodiment,however, the structures of a hitch member 14 and a lap anchor 7 and thelocking method thereof are different from those of the embodiment shownin FIGS. 6( a), 6(b).

That is, the hitch member 14 of this embodiment has a column-like body14 d and a circular or square ring-like engageable portion 14 g which isattached to one end of the body 14 d in such a manner as to swing or notto swing. The body 14 d is provided with an external thread 14 d ₁ forfixing the hitch member 14 which is formed from a middle portion to theother end of the body 14 d.

Similarly to the embodiment shown in FIGS. 6( a), 6(b), the lap anchor 7has a hole 7 a formed in a portion near an end through which the end 2 aof the seat belt 2 is passed, and a portion of the lap anchor 7extending from the middle to the other end is an engaging portion 7 b.However, the engaging portion 7 b is different from that of theembodiment shown in FIGS. 6( a), 6(b) and is a hook-like engagingportion 7 b. The hook-like engaging portion 7 b is provided with ahooking pawl 7 d ₂ forming an engaging concavity 7 d ₁.

The lap anchor 7 has a pawl-like locking member 17 which is pivotallydisposed for closing the opening of the engaging concavity 7 d ₁. Theradius of gyration of the locking member 17 and the configuration andthe size of the engaging concavity 7 d ₁ are set such that when thelocking member 17 is in a position closing the opening of the engagingconcavity 7 d ₁ as shown by solid lines, the locking member 17 is incontact with the hooking pawl 7 d ₂ and is thus prevented from rotatingin the counter clockwise direction in FIG. 7, and when the lockingmember 17 is rotated at a certain angle in the clockwise direction inFIG. 7 as shown by dotted lines, the locking member 17 can be rotatedwithout colliding with the ring-like engageable portion 14 g positionedat the left side in FIG. 7 inside the engaging concavity 7 d ₁.

Further, a retaining pin 18 is provided for retaining the locking member17 in the position closing the opening of the engaging concavity 7 d ₁.The retaining pin 18 is inserted into retaining holes 17 a (theretaining hole of the lap anchor 7 is not shown) which are formed in thelocking member 17 and the lap anchor 7, respectively and are alignedwhen the locking member 17 is in the position closing the opening of theengaging concavity 7 d ₁, thereby retaining the locking member 17 inthis position.

The hitch member 14 is attached to the seat weight sensor 8 similarly tothe embodiment shown in FIGS. 5( a), 5(b) or to the vehicle seat 9similarly to the embodiment shown in FIGS. 4( a), 4(b). The hook-likeengaging portion 7 d of the lap anchor 7 is engaged with the ring-likeengageable portion 14 g of the hitch member 14. In this case, thering-like engageable portion 14 g is passed through the opening of theengaging concavity 7 d ₁, and is then positioned on the left side inFIG. 7 inside the engaging concavity 7 d ₁. In this state, the lockingmember 17 is rotated in the counter clockwise direction in FIG. 7 to theposition closing the opening of the engaging concavity 7 d ₁. Afterthat, the retaining pin 18 is inserted into the retaining holes 17 a. Inthis manner, the lap anchor 7 fixed to the end 2 a of the seat belt 2 issecured to the hitch member 14 so that the seat belt 2 is connected tothe hitch member 14, i.e. the vehicle body.

The other structure, works and effects of the seat belt device 1 of thisembodiment are the same as those of the aforementioned embodiment shownin FIGS. 6( a), 6(b).

Though both the buckle 6 and the hitch member 14 are attached to theseat weight sensor 8 or the vehicle seat 9 in any of the aforementionedembodiments, the present invention is not limited thereto. For example,as shown in FIG. 8( a), the hitch member 14 may be attached to thevehicle body floor 11 while the buckle 6 is attached to the seat weightsensor 8. As shown in FIG. 8( b), both the buckle 6 and the hitch member14 may be attached to the vehicle body floor 11. Further, the buckle 6may be attached to the vehicle body floor while the hitch member 14 isattached to the seat weight sensor 8, but this case is not shown. Inthese cases, however, the seat weight sensor 8 is influenced by belttension from the buckle side and/or the hitch member side fixed to thevehicle body floor 11 so that the seat weight sensor 8 can not detectthe actual seat load. Accordingly, it is necessary to compensate thebelt tension influencing relative to the seat weight sensor 8.Therefore, it is preferable that both the buckle 6 and the hitch member14 are attached to the seat weight sensor 8 or the vehicle seat 9.

FIG. 9 is an illustration schematically and partially showing a lapanchor and a hitch member according to further another embodiment of thepresent invention.

As shown in FIG. 9, in a seat belt device 1 of this embodiment, an endof a slide bar 19 which also functions as the hitch member is attachedto a mounting bracket 13 of the seat weight sensor 8. The slide bar 19extends along one of the both lateral sides of the vehicle body towardthe rear of the vehicle so that the other end of the slide bar 19 isfixed to the vehicle body such as a floor 11.

As shown in FIGS. 10( a) and 10(b), a portion of the slide bar 19 on theone end side is substantially curved in a U shape to compose a hitchportion 19 a. The end 19 b of the hitch portion 19 a is attached to sidewalls 13 a of the mounting bracket 13. In this case, as shown in FIG.10( c) and FIG. 11( a), a mounting bolt 20 is inserted into a ring-shapewave washer 21, a ring-shape spacer 22, holes 13 b formed in the bothside walls 13 a, a ring-shape spacer 23, a wave washer 24, a bush 25, aCS ring 26, and a hole 19 c formed in the end 19 b of the slide bar 19and is screwed with a nut 27, thereby attaching the one end side of theslide bar 19 to the mounting bracket 13. In this case, the holes 13 bformed in the both side walls 13 a are each formed into such a circularshape allowing the insertion of the mounting bolt 20 with very littlespace as shown in FIG. 10( d).

As shown in FIG. 10( e), the slide bar 19 is also provided with anelongated hole 19 e formed in the other end 19 d thereof. As shown inFIG. 11( b), after a mounting bolt 28 is inserted into a ring-shape wavewasher 29, a ring-shape spacer 30, the hole 19 e of the slid bar 19, abush 31, a plane washer 32, and a CS ring 33, the mounting bolt 28 isscrewed into an internal thread formed in the vehicle body, therebyfixing the other end side of the slide bar 19 to the vehicle body. Sincethe hole 19 e is an elongated hole, the alignment relative to the holes13 b of the mounting bracket 13 and the hole 19 b of the slide bar 19can be easily and securely performed, thus facilitating the insertion ofthe mounting bolt.

On the other hand, as shown in FIG. 9, a lap anchor 7 is formed at theend of a lap belt portion 2 b of a seat belt 2. The lap anchor 7 isformed in a loop shape by sewing the end of the lap belt portion 2 a inthe folded state (the sewn portion is marked with A). The loop-shape lapanchor 7 is coupled with the slide bar 19 so that the lap anchor 7 canslide relative to slide bar 19. Therefore, the loop-shape lap anchor 7can be guided along the slide bar 19 to move between its workingposition a on the curved hitch portion 19 a of the slide bar 19 and itsstandby position β behind the working position a.

In the seat belt device 1 of this embodiment having the aforementionedstructure, when an occupant is seated and is about to put on the seatbelt 2, the occupant first sets the lap anchor 7 at the working positiona and then inserts a tongue 5 into a buckle 6 to latch similarly toconventional seat belt devices. In this manner, the seat belt 2 is puton. Since the lap anchor 7 is positioned at the curved portion of thehitch portion 19 a of the slide bar 19, tensile force acting on the lapbelt portion 2 b acts in a direction substantially perpendicular to thecurved portion of the hitch portion 19 a. Therefore, the lap anchor 7 isprevented from moving from the working position a, whereby the seat belt2 can securely restrain and protect the occupant in the event ofemergency.

For example, in case that the seat belt device 1 of this embodiment isinstalled to a vehicle of two-door type, when a rear seat passenger isabout to get in or out of the vehicle, the lap anchor 7 is set at thestandby position β so as to allow the rear seat passenger to get on oroff the vehicle. When the passenger gets in or out of the vehicle, thelap belt 2 b does not disturb the action of the passenger because thelap anchor 7 is set at the standby position β, thereby allowing thepassenger to easily get in or out of the vehicle. After the passengergets in the vehicle, an occupant sitting on a front seat can normallyput on the seat belt 2 by setting the lap anchor 7 at the workingposition a. The seat belt device 1 of this embodiment is not limited tothe vehicle of two-door type and is useful for vehicles of a type havinga possibility that the lap belt 2 b including the lap anchor 7 disturbsthe action of a passenger.

The other structure and the other works and effects of the seat beltdevice 1 according to this embodiment are the same as those of thepreceding embodiments.

FIGS. 12( a), 12(b) show another example of the mounting portion betweenthe seat weight sensor and the slide bar, wherein FIGS. 12 (a) and 12(b)are sectional views (sic) similar to FIGS. 10( d) and 10(e).

Though the holes 13 b are circular holes and the hole 19 e is anelongated hole in the embodiment shown in FIGS. 10( d) and 10(e), theholes 13 b are elongated holes and the hole 19 is a circular hole inthis example as shown in FIGS. 12( a) and 12(b).

The other structure and the other works and effects of the seat beltdevice 1 according to this example are the same as those of theembodiment shown in FIG. 9 through FIG. 11( b).

FIG. 13 is a sectional view similar to FIG. 10( c) showing a variationof the mounting portion between the seat weight sensor and the slidebar.

Though the mounting bolt 20 is simply inserted into the holes 13 b ofthe mounting bracket 13 in the embodiment shown in FIG. 10( c), a collar34 is disposed between the both side walls 13 a of the mounting bracket13 and another collar 35 is disposed between the side wall 13 a of themounting bracket 13 and the other end 19 d of the slide bar 19 in thisexample as shown in FIG. 13. By disposing the collars 34, 35 asmentioned above, the both side walls 13 a of the mounting bracket 13 isprevented from being deformed, thereby rigidly fixing the slide bar 19to the both side walls 13 a of the mounting bracket 13.

The other structure and the other works and effects of the seat beltdevice 1 according to this example are the same as those of theembodiment shown in FIG. 9 through FIG. 11( b).

Though the seat belt device of the present invention is adopted to athree-point seat belt device in the description of the aforementionedembodiments, the seat belt device of the present invention may beadopted to any type of seat belt devices where a seat weight sensor 8 isinstalled below a vehicle seat 9 and an end of a seat belt 2 isconnected to the seat weight sensor or a vehicle body.

A seat belt device of the present invention can be suitably applied to aseat belt device for a vehicle which is provided with a seat weightsensor, installed below a vehicle seat, for measuring a seat loadapplied to the vehicle seat, of which a seat belt for restraining andprotecting an occupant sitting on a vehicle seat is connected to avehicle body at least on a side of the vehicle seat.

The priority applications, Japanese Patent Application No. 2003-16498,filed on Jan. 24, 2003 and Japanese Patent Application No. 2003-290194,filed on Aug. 8, 2003, including the specification, drawings, claims andabstract, are incorporated herein by reference in their entirety.

Given the disclosure of the present invention, one versed in the artwould appreciate that there may be other embodiments and modificationswithin the scope and spirit of the invention. Accordingly, allmodifications attainable by one versed in the art from the presentdisclosure within the scope and spirit of the present invention are tobe included as further embodiments of the present invention. The scopeof the present invention is to be defined as set forth in the followingclaims.

1. A seat belt device comprising a seat belt for restraining andprotecting an occupant sitting on a vehicle seat, and a lap anchor fixedto an end of the seat belt, wherein the seat belt is connected to avehicle component on a side of the vehicle seat via the lap anchor, aseat weight sensor installed below the vehicle seat measures a seat loadapplied to said vehicle seat, and the action of the seat belt device iscontrolled on the basis of the measured value of the seat load, whereinsaid lap anchor is locked to a hitch member by an engaging hook of thelap anchor, and wherein the hitch member is directly attached to amounting bracket of the seat weight sensor, the mounting bracketpositioned between a seat rail and the seat weight sensor.
 2. The seatbelt device of claim 1, wherein the hitch member includes a supportingmember and a casing, the supporting member connected to the mountingbracket, and the casing including an insertion opening to receive theengaging hook.
 3. The seat belt device of claim 1, wherein the engaginghook includes an engaging concavity to engage and lock with the hitchmember.
 4. The seat belt device of claim 1, wherein the lap anchor isunreleasably locked to the hitch member.
 5. The seat belt device ofclaim 1, wherein the lap anchor is releasably locked to the hitchmember.
 6. A seat belt device, comprising: a hitch member directlyattached to a mounting bracket of a seat weight sensor, the mountingbracket positioned between a seat rail and the seat weight sensor; a lapanchor attached to a hitch member; wherein the lap anchor comprises anengageable hook to lock to the hitch member.
 7. The seat belt device ofclaim 6, wherein the seat weight sensor is positioned underneath avehicle seat.
 8. The seat belt device of claim 6, further comprising abuckle attached to the seat weight sensor.
 9. The seat belt device ofclaim 6, wherein the lap anchor is unreleasably locked to the hitchmember.
 10. The seat belt device of claim 6, wherein the lap anchor isreleasably locked to the hitch member.